The other Big Dig

Quick, how do you repair the 65 years' worth of decay in the longest tunnel in the world while keeping the billion gallons of water per day it delivers to 9 million thirsty New Yorkers flowing?
Answer: With a fancy computer program and a giant plug.
Today, the Department of Environmental Protection announced the next phase in a public works project that makes digging a tunnel under the city of Boston look easy: updating the Delaware Aqueduct, which has transported the water from four reservoirs in upstate New York to taps in New York City without any significant repairs since 1944.
The 85-mile-long tunnel has become notoriously leaky in recent years, and this fall, the DEP will close off an entire section of it for three weeks in order to install a plug that will keep workers installing repair equipment dry and alive. From the DEP's press release:




